High speed current collection

ABSTRACT

The coupling between a high speed electrically powered vehicle and an overhead catenary wire current distribution system is enhanced by providing compensation separately for low amplitude dynamic displacements of a wire contacting current collector which occur at different frequencies.

United States Patent 1191 1111 3,812,304 Leger 51 May 21, 1974 HIGH SPEED CURRENT COLLECTION 1,289,572 12/1918 Szafranski 191/64 [75] Inventor: Roland Leger, Paris, France [73] Assignee: Faiveley S.A., Saint Ouen, France m y a n en on ood, J Filed: Mar. 22, 1972 Assistant Exammer--D. W. Keen [21] Appl. No.: 236,874

[57] ABSTRACT [52] US. Cl. 191/66 [51] Int. Cl B601 /12 The coupling between a high speed electrically pow- Field 0f Search n 47, v ered vehicle and an overhead catenary wire current 59.3, 66, 67, distribution system is enhanced by providing compen- 68, 69, sation separately for low amplitude dynamic displacements of a wire contacting current collector which [56] Refere ce C e occur at different frequencies.

UNITED STATES PATENTS 596,193 12/1897 Wagenhals 191/66 4 Claims, 2 Drawing Figures wwmw m 1914 3 8 12.3 04

FIG.

HIGH SPEED CURRENT COLLECTION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the transfer of current to and/or from an overhead catenary wire distribution system and particularly to such current transfer during high speed motion between the current collector and the catenary. More specifically, the present invention relates to support apparatus for the electrical pick-up devices employed on high speed electrically powered vehicles. Accordingly, the general objects of the present invention are to provide novel and im proved methods and apparatus of such character.

2. Description of the Prior Art In application Ser. No. 58,971 filed July 28, 1970 and entitled Method and Apparatus for Transferring Electrical Energy to High Speed Apparatus, now U.S. Pat. No. 3,730,312 issued May 1, 1973, the present applicant disclosed a system for high-speed current collection characterized in that, for a pre-determined catenary, the periodical vertical displacement of low amplitude of the catenary due to the movement of a vehicle on the one hand and the vertical displacement of a greater amplitude due to the shape of the static profile of the catenary on the other hand, are taken up separately by two distinct support devices. The disclosure of U.S. Pat. No. 3,730,312 is incorporated herein by reference.

Recent tests have shown that it is possible to further improve the quality of current collection or transfer by detecting separately, among the low-amplitude vertical displacements, those which originate from the shock of the pantograph slipper against the hard points. A first source of hard points is the points where the catenary is suspended from support posts. The standard spacing of such posts is, in the majority of countries, 63 metres. Further low-amplitude vertical displacements originate from the impact of the pantograph slipper against further hard points which correspond to the auxiliary suspension points of the catenary between two successive support posts. Accordingly, there are two periodic displacement phenomena of different frequencies. These two periodic phenomena will be referred to herein as low and larger frequency oscillations respectively.

The equipment envisaged in U.S. Pat..No. 3,730,312 is characterized by a first support constituting a suspension and current pick-up device; the suspension being designed to have sufficient amplitude to enable the equipment to take-up the low amplitude periodic displacements; and a second support which carries the first support and which constitutes the lower lifting structure; the second support being designed to carry out subsidiary take-up of the large amplitude displacements,

U.S. Pat. No. 3,730,312 further teaches the advisability of damping the movements of the second support either by using a shock absorber of a known type or by using a friction braking device. Also, the copending application suggests the use, for the suspension of the horned slipper holder on the first support, of known resilient suspension devices.

SUMMARY OF THE INVENTION In accordance with the present invention, the flexible suspension means of the slipper on the first support is combined with the first support in such a way as to detect and separate the low-amplitude and low-frequency movements on the one hand and the low-amplitude greater frequency movements on the other hand, both being defined as above.

The present invention envisions providing the first support either with a shock absorber of a known type or of a friction device so that this first support is practically insensitive to the low-amplitude and larger frequency oscillations, whilst the slipper suspension springs on the first support are designed to take-up the low-amplitude and low frequency oscillations.

It will easily be realized that a device of this nature offers very great advantages in that it can equally be engaged under a catenary of the former type with sags which are frequently important between the support points, or below modern catenaries in which the intermediate points of suspension are multiplied in order to approach the ideal rectilinear path.

The present invention, with its three superimposed devices, preferably employs slippers of very light weight. An advantage of the present invention consists in permitting the reduction in weight of the slipper by eliminating the usual horns which are used to impose the relative movement on the slipper; which movements, at the crossings, causing the catenary to rise on the slipper. The horns will therefore be advantageously fitted to the first support and not to the slipper. It will, however, also be sufficient to provide ramps which faeilitate the movement of the catenary on the horns of the slipper.

BRIEF DESCRIPTION OF THE DRAWING The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the several figures and in which:

FIG. 1 shows the upper part of the apparatus shown in FIG. 3 of U.S. Pat. No. 3,730,312 as modified in accordance with the present invention; and

FIG. 2 showsthe upper part of the apparatus of FIG. 4 of U.S. Pat. No. 3,730,312 as modified in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As is seen on FIG. 1 herein, the equipment is similar to that shown on FIG. 3 of U.S. Pat. No. 3,730,312 with the important distinction of the addition of a shock absorber 100. Shock absorber can be of any known type, for example a hydraulic shock absorber or a dry friction shock absorber, and is hinged at 101 on support 61 and at 102 on the upper rod of device 71. Device 71 functions as the first support as described in detail in U.S. Pat. No. 3,730,312.

In FIG. 2 the first support, is indicated at 71 and includes connecting rods 75 and 76. These rods support, as previously, horns and 111. However, by way of contrast to the apparatus of U.S. Pat. No. 3,730,312, the pantograph wearing strips or shoes 1 12, which constitute the slipperproper, are not supported directly by the first support 71. Rather, the current collector or collectors 112 are mounted from the first support 71 by means of springs represented schematically at 113 and 114. Through the arrangement of FIG. 2 the mass of the equipment, which is suspended and which forms the current collector proper, is reduced to its minimum since part 112 comprises only the wear strips.

The present invention also solves a problem of long standing in the art. Great collection difficulties have previously been found when it was wished to make up trains of large length by grouping several propulsion units. The movements imposed on the catenary by the collector of the first propulsion unit adversely affected subsequent current collection, even at relatively low speeds (e.g., 100 km/hour), and the difficulty increased with the number of units. Owing to the fact that the movements imposed on the catenary using the collection process in accordance with the present invention are substantially reduced in amplitude and in acceleration, adverse unit-to-unit effects are reduced to an acceptable level.

While a preferred embodiment has been shown and described, various modifications and substitutions may be made without departing from the spirit and scope of this invention. Accordingly, it is to be understood that this invention has been described by way of illustration and not limitation.

being adapted to provide compensation for low amplitude and low frequency displacements of said current collector resulting from interaction between said current collector and the catenary wire;

second resilient support means, said second resilient support means serving as a lifting structure for the apparatus and being adapted to provide compensation for comparatively large amplitude displacements of said current collector resulting from the shape of the static profile of the catenary wire, said first support means being mounted on said second support means; and

third resilient support means mounted on said first support means, said third support means being adapted to provide compensation for dynamic low amplitude displacements of said current collector greater frequency than said low frequency.

2. The apparatus of claim 1 wherein the current collector is mounted from said first support means by said third support means.

3. The apparatus of claim 2 further comprising:

catenary lifting arms extending from said first support means.

4. The apparatus of claim 1' wherein said third support means provides for damping of movements of said first support means. 

1. Apparatus for use in the transfer of current from an overhead catenary wire distribution system to current utilizing equipment comprising: a current collector for contacting a catenary wire; first resilient support means, said first support means being adapted to provide compensation for low amplitude and low frequency displacements of said current collector resulting from interaction between said current collector and the catenary wire; second resilient support means, said second resilient support means serving as a lifting structure for the apparatus and being adapted to provide compensation for comparatively large amplitude displacements of said current collector resulting from the shape of the static profile of the catenary wire, said first support means being mounted on said second support means; and third resilient support means mounted on said first support means, said third support means being adapted to provide compensation for dynamic low amplitude displacements of said current collector greater frequency than said low frequency.
 2. The apparatus of claim 1 wherein the current collector is mounted from said first support means by said third support means.
 3. The apparatus of claim 2 further comprising: catenary lifting arms extending from said first support means.
 4. The apparatus of claim 1 wherein said third support means provides for damping of movements of said first support means. 